1. Field of the Invention:
The invention relates to a catalyst for the selective reduction of nitrogen oxides in waste gases by means of ammonia.
2. Description of the Prior Art:
Such catalysts are known, specifically, for example, catalysts containing Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3 or V.sub.2 O.sub.5. In terms of their action, however, these catalysts leave something to be desired.
Some examples of catalytic technology are found in U.S. Pat. No. 4,259,312, entitled "Process And Apparatus For Catalytically Reacting A Reducing Gas And Water Vapor"; U.S. Pat. No. 4,235,604, entitled "Method For Processing Coke Oven Gas"; and U.S. Pat. No. 4,049,777, entitled "Method Of Waste Gas Treatment", all of which are assigned the same assignee as the instant application.
Further examples of catalytic technology are found in U.S. Pat. No. 4,448,895, entitled "Process For Preparation Of Catalyst For Cleaning Exhaust Gases And Catalyst Prepared For The Process", and U.S. Pat. No. 4,503,162, entitled "Catalyst Systems For The Conversion Of Gases".
Examples of reactivation of catalysts useful in nitrogen oxide removal are described in U.S. Pat. No. 4,044,102, entitled "Method For Treating Exhaust Gases", and U.S. Pat. No. 4,043,939, entitled "Reactivation Of Catalysts Useful For Nitrogen Oxide Removal." All of the above-cited patents are incorporated herein by reference as if the texts thereof were fully set forth herein.